英语compound word问题

题目

英语compound word问题
题目是3个单词对1个单词 且都能组成3个新的单词
类似：base；basket；snow+ball=baseball；basketball；snowball
我现在需要school；class；bed
sail；speed；motor
flash；day；stop
ear；back；head
hand；lithe；win
half；running；quarter
rose；balsa；fruit
card；black；back
上面这些组加什么才能组成新的单词呢.（注意,必须是同时满足三个的单词,ing；er之类的不行.必须是单词）

答案

room:schoolroom,classroom,bedroomboat:sailboat,speedboat,motorboatlight:flashlight,daylight,stoplightache:earache,backache,headachesome:handsome,lithesome,winsomeback:halfback,running back,quarterback...